When it is desired to hook a painting or a similar flat object such as a mirror on a wall, a cord joining the two uprights of the frame of the painting must generally firstly be fixed, or one or more rings must be fixed at the rear of the painting. The painting is then hung via this cord or this or these rings, on one or more support elements fixed in the wall, for example nails, plugs or hooks such as the one described in U.S. Pat. No. 2,940,712. This document describes a hook provided with a nail presenting a "V" shaped body which comprises a notched slot, as well as a tapering point and a head: a second threaded anchoring nail (or screw) extends through the notched slot; the first nail is inclined upwardly by an angle ranging from 35 to 45.degree. with respect to the horizontal, while the second (anchoring) nail is inclined downwardly.
It is difficult to manage to position the painting precisely. In fact, when several support elements are used, unimportant variations in alignment may nonetheless provoke an inclined position of the painting detrimental to its aesthetic appearance and to the general presentation of the wall. When a single support element is used, the painting is then in even more precarious equilibrium, and may pivot accidentally due to the cord sliding around its single point of support, and take a considerably inclined position.
Furthermore, if it is desired to modify the position of the painting in height, it is necessary either to fix a new support element in the wall, or modify the length of the cord, which process is fastidious.
U.S. Pat. No. 2,791,388 discloses a device for supporting and positioning a painting, which comprises:
a support comprising two lugs, to be fixed to the wall by nails, screws or an adhesive, and comprising a threaded opening; PA1 a body likewise comprising two lugs to be fixed to the frame by fixing members such as nails screws or adhesive, PA1 two threaded rods fixed to the body and provided with a nut, PA1 a base which may slide horizontally with respect to the support to allow a horizontal displacement of the frame. PA1 said supporting and positioning device (for hooking or hanging) a flat object provided with a protuberant element on its rear face, on a substantially vertical surface, comprises: PA1 an intermediate fixing body or element which comprises a threaded passage (or tapped hole), PA1 means for fixing to said wall (to said surface) said intermediate fixing body or element, PA1 an element for positioning (or adjustment) or vertical displacement and support of said object or painting, which comprises: PA1 said element forming bracket (of said second end part) comprises on an upper horizontal bearing face, on which said frame may be hanged by its said horizontal plane face or zone, which comprises friction or friction or adhesion means adapted to cooperate with said hanging face of said frame, which means preferably comprise one or more (preferably tapered conical or pyramidal) tacks or brads adapted to penetrate at least partly (by marking or stamping) in said hanging face of said frame made of a material of low hardness, such as wood or a plastics material; PA1 said body comprises at least one through hole (preferably two) or slot, extending between front face and rear face of the block, adapted to receive a curved metal blade forming one of said means for fixing said body to said surface, which blade is preferably essentially constituted by a portion of bent or rolled metal plate (or foil or thin section), which through hole or slot is substantially cylindrical, of circular section or not; PA1 said body comprises at least two (preferably at least four) guiding through holes or slots, extending between front face and rear face of the block, adapted to receive at least two different means (for example three different means) for fixing said body to said surface; PA1 said body is provided with two parallel, principal, large faces: a rear face in contact with the surface and a front face by which the fixing means are introduced in said holes or slots; PA1 said holes or slots, as well as the lower and tipper faces of the body, are inclined with respect to the normal to a rear face for abutment of the body against said surface, by an angle included between 5 and 45 degrees, preferably ranging from 15 to 35 degrees, for example close to 20 to 30 degrees; PA1 said device comprises a face for abutment against said surface for example integrated in said intermediate fixing body or element, which is adhesive; PA1 said device further comprises a base or interposed adapter of flattened shape, for example in the general form of a shoe, which comprises integrated means for mechanical fixing or connection with said intermediate fixing body or element, which comprises a rear face in contact with said surface (whose surface is larger than the various surfaces of the faces of said body), which is coated with an adhesive, and said interposed piece or adapter further preferably comprises at least one and preferably at least two through orifices for guiding accessory means (such as tacks or nails) for fixing said adapter to said surface, which means for mechanical connection with said intermediate fixing body or element preferably comprise at least one slide element (male or female respectively) adapted to cooperate with a slide element (female or male respectively) with which said intermediate fixing body or element is provided, which adapter further comprises at least one stop; PA1 said intermediate fixing body or element is made of plastics material; PA1 said positioning or displacement and supporting element is essentially constituted by a screw, made of plastics material or metal, provided with a tapering point; PA1 said intermediate fixing body or element is in the form of a cylindrical portion, of rounded rectangular section for example, preferably oblique, i.e. of which the axis of the cylinder is inclined with respect to the base, which axis is preferably parallel to the axes of said tack, blade and screw housings; PA1 the device comprises at least two blades of the same section (or profile) and of different length, and/or comprises at least two blades of section of the same shape (or profile) and of different width. PA1 a tool for adjusting by screwing or unscrewing the screw bearing the bracket; PA1 a removable rectilinear positioning rule provided on a lower face with at least two housings for insertion of the upper ends of the threaded rods, these housings being of the same depth, with a view to adjusting to the horizontal the ends of the threaded rods; these housings are bored and present a thread corresponding to that of the threaded rods. PA1 a first bar elongated along a first longitudinal axis, PA1 as the case may be, a second bar elongated along a second longitudinal axis perpendicular to said first axis, preferably mounted to slide along its longitudinal axis with respect to said first bar, and comprising distance measuring graduations, PA1 a substantially plane rear face adapted to be applied against the outer face of said surface, PA1 at least one (preferably several) first cavity (cavities) adapted to receive at least a portion of an intermediate body or element for fixing (the painting), and with a thickness or depth such that said body may be housed at least partly in said first cavity with its rear face substantially flush with the rear face of the first bar, which first cavity opens out on a front face of the first bar via an orifice allowing free passage and slide of said means for fixing the body, for impacting them in said wall, PA1 at least one (preferably several) second cavity (cavities) adapted to receive at least a portion of an element (such as a screw) for positioning and supporting (the painting) which is screwed in said intermediate fixing element, which second cavity communicates with said first cavity and preferably extends along a longitudinal axis perpendicular to said longitudinal axis of the first bar, which second cavity opens out on a lower face as well as on an upper face of said first bar.